Design of an antenna array for a passive mm-wave imager

In this paper the off-axis performance of an imaging array for an opto mechanical mm-wave imaging system has been studied. The analysed system consists of a spherical mirror and a plane polarizer. Both components are tilted to scan a vertical line. In order to avoid the beam degradation of the off-axis elements of the array a curved arrangement has been studied. The radius of this curvature has been analysed with a ray tracing program (OSLO) and a physical optics reflector antenna analysis software (GRASP) that can calculate the electromagnetic radiation of systems consisting of multiple reflectors. However, the performance achieved has been found to be similar to the performance of the planar array.